Metal alloy powders, such as titanium alloy powders have both mechanical and corrosion resistance properties and can be used as structural materials in many industrial areas. Such areas include aerospace, automotive industries, chemical engineering industries, and even military hardware applications. This usefulness is primarily due to the characteristics of metal alloy powders such as their weight to strength ratio, oxidation resistance, and wear resistance amongst other characteristics. As a result, production of metal alloy powder, in particular titanium alloy powders, is always under constant investigation.
For example, titanium aluminides have been used as structural materials, coatings, and forming and near net shapes by applying powder metallurgy technology.
While titanium is the fourth most abundant metal in the earth's crust (0.86% by weight) behind aluminium, iron and magnesium, titanium alloys are not particularly widely used primarily due to the cost of processing the material. Similarly for the production of other metals and metal alloys, the cost and processing requirements are prohibitive.
There are a number of processes for the production of metals and metal alloy materials that have been described in the patent literature including, for example, that described in PCT/NZ2003/00159 entitled “A Separation Process” also to Titanox Development Limited. This document teaches the manufacture of metal alloy powders (e.g. TiAl) via a coarsening and separation step. This can then be followed by further reduction step using, amongst other reducing agents, calcium hydride. U.S. Pat. No. 6,231,636 to Froes et al teaches a mechanochemical process for producing Ti metals. The process uses a reduction reaction between a reducible metal compound (such as the chloride) and a metal hydride, by mechanochemical processing.